/*
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
package net.sf.l2j.gameserver;

import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.logging.Logger;

import javolution.text.TextBuilder;
import net.sf.l2j.Config;
import net.sf.l2j.gameserver.network.L2GameClient;

import org.mmocore.network.ReceivablePacket;

/**
 * <p>
 * This class is made to handle all the ThreadPools used in L2j.
 * </p>
 * <p>
 * Scheduled Tasks can either be sent to a {@link #_generalScheduledThreadPool
 * "general"} or {@link #_effectsScheduledThreadPool "effects"}
 * {@link ScheduledThreadPoolExecutor ScheduledThreadPool}: The "effects" one is
 * used for every effects (skills, hp/mp regen ...) while the "general" one is
 * used for everything else that needs to be scheduled.<br>
 * There also is an {@link #_aiScheduledThreadPool "ai"}
 * {@link ScheduledThreadPoolExecutor ScheduledThreadPool} used for AI Tasks.
 * </p>
 * <p>
 * Tasks can be sent to {@link ScheduledThreadPoolExecutor ScheduledThreadPool}
 * either with:
 * <ul>
 * <li>{@link #scheduleEffect(Runnable, long)} : for effects Tasks that needs to
 * be executed only once.</li>
 * <li>{@link #scheduleGeneral(Runnable, long)} : for scheduled Tasks that needs
 * to be executed once.</li>
 * <li>{@link #scheduleAi(Runnable, long)} : for AI Tasks that needs to be
 * executed once</li>
 * </ul>
 * or
 * <ul>
 * <li>{@link #scheduleEffectAtFixedRate(Runnable, long, long)(Runnable, long)}
 * : for effects Tasks that needs to be executed periodicaly.</li>
 * <li>{@link #scheduleGeneralAtFixedRate(Runnable, long, long)(Runnable, long)}
 * : for scheduled Tasks that needs to be executed periodicaly.</li>
 * <li>{@link #scheduleAiAtFixedRate(Runnable, long, long)(Runnable, long)} :
 * for AI Tasks that needs to be executed periodicaly</li>
 * </ul>
 * </p>
 * <p>
 * For all Tasks that should be executed with no delay asynchronously in a
 * ThreadPool there also are usual {@link ThreadPoolExecutor ThreadPools} that
 * can grow/shrink according to their load.:
 * <ul>
 * <li>{@link #_generalPacketsThreadPool GeneralPackets} where most packets
 * handler are executed.</li>
 * <li>{@link #_ioPacketsThreadPool I/O Packets} where all the i/o packets are
 * executed.</li>
 * <li>There will be an AI ThreadPool where AI events should be executed</li>
 * <li>A general ThreadPool where everything else that needs to run
 * asynchronously with no delay should be executed (
 * {@link net.sf.l2j.gameserver.model.actor.knownlist KnownList} updates, SQL
 * updates/inserts...)?</li>
 * </ul>
 * </p>
 * 
 * @author -Wooden-
 */
public class ThreadPoolManager {
	private static final Logger _log = Logger.getLogger(ThreadPoolManager.class
			.getName());
	private static ThreadPoolManager _instance;
	private ScheduledThreadPoolExecutor _effectsScheduledThreadPool;
	private ScheduledThreadPoolExecutor _generalScheduledThreadPool;
	private ThreadPoolExecutor _generalPacketsThreadPool;
	private ThreadPoolExecutor _ioPacketsThreadPool;
	// will be really used in the next AI implementation.
	private ThreadPoolExecutor _aiThreadPool;
	private ThreadPoolExecutor _generalThreadPool;
	// temp
	private ScheduledThreadPoolExecutor _aiScheduledThreadPool;
	private boolean _shutdown;

	public static ThreadPoolManager getInstance() {
		if (_instance == null)
			_instance = new ThreadPoolManager();
		return _instance;
	}

	private ThreadPoolManager() {
		_effectsScheduledThreadPool = new ScheduledThreadPoolExecutor(
				Config.THREAD_P_EFFECTS, new PriorityThreadFactory(
						"EffectsSTPool", Thread.MIN_PRIORITY));
		_generalScheduledThreadPool = new ScheduledThreadPoolExecutor(
				Config.THREAD_P_GENERAL, new PriorityThreadFactory(
						"GerenalSTPool", Thread.NORM_PRIORITY));
		_aiScheduledThreadPool = new ScheduledThreadPoolExecutor(
				Config.AI_MAX_THREAD, new PriorityThreadFactory("AISTPool",
						Thread.NORM_PRIORITY - 3));
		_ioPacketsThreadPool = new ThreadPoolExecutor(
				Config.IO_PACKET_THREAD_CORE_SIZE, Integer.MAX_VALUE, 5L,
				TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>(),
				new PriorityThreadFactory("I/O Packet Pool",
						Thread.NORM_PRIORITY + 2));
		_generalPacketsThreadPool = new ThreadPoolExecutor(
				Config.GENERAL_PACKET_THREAD_CORE_SIZE,
				Config.GENERAL_PACKET_THREAD_CORE_SIZE * 2, 15L,
				TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>(),
				new PriorityThreadFactory("Normal Packet Pool",
						Thread.NORM_PRIORITY + 1));
		_generalThreadPool = new ThreadPoolExecutor(
				Config.GENERAL_THREAD_CORE_SIZE,
				Config.GENERAL_THREAD_CORE_SIZE * 2, 5L, TimeUnit.SECONDS,
				new LinkedBlockingQueue<Runnable>(), new PriorityThreadFactory(
						"General Pool", Thread.NORM_PRIORITY));
		// will be really used in the next AI implementation.
		_aiThreadPool = new ThreadPoolExecutor(Config.AI_MAX_THREAD,
				Config.AI_MAX_THREAD * 2, 10L, TimeUnit.SECONDS,
				new LinkedBlockingQueue<Runnable>(), new PriorityThreadFactory(
						"Ai Pool", Thread.NORM_PRIORITY - 1));
		// Set Allowing terminating deatlock threads
		_ioPacketsThreadPool.allowCoreThreadTimeOut(true);
		_generalPacketsThreadPool.allowCoreThreadTimeOut(true);
		_generalThreadPool.allowCoreThreadTimeOut(true);
		_aiThreadPool.allowCoreThreadTimeOut(true);
		// pestaring all core threads for not lost times
		_log.config("ThreadPoolManager: "
				+ _ioPacketsThreadPool.prestartAllCoreThreads()
				+ " I/O Core threads prestarted...");
		_log.config("ThreadPoolManager: "
				+ _generalPacketsThreadPool.prestartAllCoreThreads()
				+ " General Packets Core threads prestarted...");
		_log.config("ThreadPoolManager: "
				+ _generalThreadPool.prestartAllCoreThreads()
				+ " General Task Core threads prestarted...");
		_log.config("ThreadPoolManager: "
				+ _aiThreadPool.prestartAllCoreThreads()
				+ " Ai Core threads prestarted...");
	}

	@SuppressWarnings("unchecked")
	public ScheduledFuture scheduleEffect(Runnable r, long delay) {
		try {
			if (delay < 0)
				delay = 0;
			return _effectsScheduledThreadPool.schedule(r, delay,
					TimeUnit.MILLISECONDS);
		} catch (RejectedExecutionException e) {
			return null; /* shutdown, ignore */
		}
	}

	@SuppressWarnings("unchecked")
	public ScheduledFuture scheduleEffectAtFixedRate(Runnable r, long initial,
			long delay) {
		try {
			if (delay < 0)
				delay = 0;
			if (initial < 0)
				initial = 0;
			return _effectsScheduledThreadPool.scheduleAtFixedRate(r, initial,
					delay, TimeUnit.MILLISECONDS);
		} catch (RejectedExecutionException e) {
			return null; /* shutdown, ignore */
		}
	}

	@SuppressWarnings("unchecked")
	public ScheduledFuture scheduleGeneral(Runnable r, long delay) {
		try {
			if (delay < 0)
				delay = 0;
			return _generalScheduledThreadPool.schedule(r, delay,
					TimeUnit.MILLISECONDS);
		} catch (RejectedExecutionException e) {
			return null; /* shutdown, ignore */
		}
	}

	@SuppressWarnings("unchecked")
	public ScheduledFuture scheduleGeneralAtFixedRate(Runnable r, long initial,
			long delay) {
		try {
			if (delay < 0)
				delay = 0;
			if (initial < 0)
				initial = 0;
			return _generalScheduledThreadPool.scheduleAtFixedRate(r, initial,
					delay, TimeUnit.MILLISECONDS);
		} catch (RejectedExecutionException e) {
			return null; /* shutdown, ignore */
		}
	}

	@SuppressWarnings("unchecked")
	public ScheduledFuture scheduleAi(Runnable r, long delay) {
		try {
			if (delay < 0)
				delay = 0;
			return _aiScheduledThreadPool.schedule(r, delay,
					TimeUnit.MILLISECONDS);
		} catch (RejectedExecutionException e) {
			return null; /* shutdown, ignore */
		}
	}

	@SuppressWarnings("unchecked")
	public ScheduledFuture scheduleAiAtFixedRate(Runnable r, long initial,
			long delay) {
		try {
			if (delay < 0)
				delay = 0;
			if (initial < 0)
				initial = 0;
			return _aiScheduledThreadPool.scheduleAtFixedRate(r, initial,
					delay, TimeUnit.MILLISECONDS);
		} catch (RejectedExecutionException e) {
			return null; /* shutdown, ignore */
		}
	}

	public void executePacket(ReceivablePacket<L2GameClient> pkt) {
		_generalPacketsThreadPool.execute(pkt);
	}

	public void executeIOPacket(ReceivablePacket<L2GameClient> pkt) {
		_ioPacketsThreadPool.execute(pkt);
	}

	public void executeTask(Runnable r) {
		_generalThreadPool.execute(r);
	}

	public void executeAi(Runnable r) {
		_aiThreadPool.execute(r);
	}

	public String[] getStats() {
		return new String[] {
				"Scheduled Thread Pools:",
				" + Effects:",
				" |- ActiveThreads:   "
						+ _effectsScheduledThreadPool.getActiveCount(),
				" |- getCorePoolSize: "
						+ _effectsScheduledThreadPool.getCorePoolSize(),
				" |- PoolSize:        "
						+ _effectsScheduledThreadPool.getPoolSize(),
				" |- MaximumPoolSize: "
						+ _effectsScheduledThreadPool.getMaximumPoolSize(),
				" |- CompletedTasks:  "
						+ _effectsScheduledThreadPool.getCompletedTaskCount(),
				" |- ScheduledTasks:  "
						+ (_effectsScheduledThreadPool.getTaskCount() - _effectsScheduledThreadPool
								.getCompletedTaskCount()),
				" | -------",
				" + General:",
				" |- ActiveThreads:   "
						+ _generalScheduledThreadPool.getActiveCount(),
				" |- getCorePoolSize: "
						+ _generalScheduledThreadPool.getCorePoolSize(),
				" |- PoolSize:        "
						+ _generalScheduledThreadPool.getPoolSize(),
				" |- MaximumPoolSize: "
						+ _generalScheduledThreadPool.getMaximumPoolSize(),
				" |- CompletedTasks:  "
						+ _generalScheduledThreadPool.getCompletedTaskCount(),
				" |- ScheduledTasks:  "
						+ (_generalScheduledThreadPool.getTaskCount() - _generalScheduledThreadPool
								.getCompletedTaskCount()),
				" | -------",
				" + AI:",
				" |- ActiveThreads:   "
						+ _aiScheduledThreadPool.getActiveCount(),
				" |- getCorePoolSize: "
						+ _aiScheduledThreadPool.getCorePoolSize(),
				" |- PoolSize:        " + _aiScheduledThreadPool.getPoolSize(),
				" |- MaximumPoolSize: "
						+ _aiScheduledThreadPool.getMaximumPoolSize(),
				" |- CompletedTasks:  "
						+ _aiScheduledThreadPool.getCompletedTaskCount(),
				" |- ScheduledTasks:  "
						+ (_aiScheduledThreadPool.getTaskCount() - _aiScheduledThreadPool
								.getCompletedTaskCount()),
				"Thread Pools:",
				" + Packets:",
				" |- ActiveThreads:   "
						+ _generalPacketsThreadPool.getActiveCount(),
				" |- getCorePoolSize: "
						+ _generalPacketsThreadPool.getCorePoolSize(),
				" |- MaximumPoolSize: "
						+ _generalPacketsThreadPool.getMaximumPoolSize(),
				" |- LargestPoolSize: "
						+ _generalPacketsThreadPool.getLargestPoolSize(),
				" |- PoolSize:        "
						+ _generalPacketsThreadPool.getPoolSize(),
				" |- CompletedTasks:  "
						+ _generalPacketsThreadPool.getCompletedTaskCount(),
				" |- QueuedTasks:     "
						+ _generalPacketsThreadPool.getQueue().size(),
				" | -------",
				" + I/O Packets:",
				" |- ActiveThreads:   " + _ioPacketsThreadPool.getActiveCount(),
				" |- getCorePoolSize: "
						+ _ioPacketsThreadPool.getCorePoolSize(),
				" |- MaximumPoolSize: "
						+ _ioPacketsThreadPool.getMaximumPoolSize(),
				" |- LargestPoolSize: "
						+ _ioPacketsThreadPool.getLargestPoolSize(),
				" |- PoolSize:        " + _ioPacketsThreadPool.getPoolSize(),
				" |- CompletedTasks:  "
						+ _ioPacketsThreadPool.getCompletedTaskCount(),
				" |- QueuedTasks:     "
						+ _ioPacketsThreadPool.getQueue().size(),
				" | -------",
				" + General Tasks:",
				" |- ActiveThreads:   " + _generalThreadPool.getActiveCount(),
				" |- getCorePoolSize: " + _generalThreadPool.getCorePoolSize(),
				" |- MaximumPoolSize: "
						+ _generalThreadPool.getMaximumPoolSize(),
				" |- LargestPoolSize: "
						+ _generalThreadPool.getLargestPoolSize(),
				" |- PoolSize:        " + _generalThreadPool.getPoolSize(),
				" |- CompletedTasks:  "
						+ _generalThreadPool.getCompletedTaskCount(),
				" |- QueuedTasks:     " + _generalThreadPool.getQueue().size(),
				" | -------",
				" + AI:",
				" |- ActiveThreads:   " + _aiThreadPool.getActiveCount(),
				" |- getCorePoolSize: " + _aiThreadPool.getCorePoolSize(),
				" |- MaximumPoolSize: " + _aiThreadPool.getMaximumPoolSize(),
				" |- LargestPoolSize: " + _aiThreadPool.getLargestPoolSize(),
				" |- PoolSize:        " + _aiThreadPool.getPoolSize(),
				" |- CompletedTasks:  " + _aiThreadPool.getCompletedTaskCount(),
				" |- QueuedTasks:     " + _aiThreadPool.getQueue().size() };
	}

	private class PriorityThreadFactory implements ThreadFactory {
		private int _prio;
		private String _name;
		private AtomicInteger _threadNumber = new AtomicInteger(1);
		private ThreadGroup _group;

		public PriorityThreadFactory(String name, int prio) {
			_prio = prio;
			_name = name;
			_group = new ThreadGroup(_name);
		}

		/*
		 * (non-Javadoc)
		 * 
		 * @see java.util.concurrent.ThreadFactory#newThread(java.lang.Runnable)
		 */
		public Thread newThread(Runnable r) {
			Thread t = new Thread(_group, r);
			t.setName(_name + "-" + _threadNumber.getAndIncrement());
			t.setPriority(_prio);
			return t;
		}

		public ThreadGroup getGroup() {
			return _group;
		}
	}

	/**
     *
     */
	public void shutdown() {
		_shutdown = true;
		try {
			_effectsScheduledThreadPool.awaitTermination(1, TimeUnit.SECONDS);
			_generalScheduledThreadPool.awaitTermination(1, TimeUnit.SECONDS);
			_generalPacketsThreadPool.awaitTermination(1, TimeUnit.SECONDS);
			_ioPacketsThreadPool.awaitTermination(1, TimeUnit.SECONDS);
			_generalThreadPool.awaitTermination(1, TimeUnit.SECONDS);
			_aiThreadPool.awaitTermination(1, TimeUnit.SECONDS);
			_effectsScheduledThreadPool.shutdown();
			_generalScheduledThreadPool.shutdown();
			_generalPacketsThreadPool.shutdown();
			_ioPacketsThreadPool.shutdown();
			_generalThreadPool.shutdown();
			_aiThreadPool.shutdown();
			System.out.println("All ThreadPools are now stoped");
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	public boolean isShutdown() {
		return _shutdown;
	}

	/**
     *
     */
	public void purge() {
		_effectsScheduledThreadPool.purge();
		_generalScheduledThreadPool.purge();
		_aiScheduledThreadPool.purge();
		_ioPacketsThreadPool.purge();
		_generalPacketsThreadPool.purge();
		_generalThreadPool.purge();
		_aiThreadPool.purge();
	}

	/**
     *
     */
	public String getPacketStats() {
		TextBuilder tb = new TextBuilder();
		ThreadFactory tf = _generalPacketsThreadPool.getThreadFactory();
		if (tf instanceof PriorityThreadFactory) {
			tb.append("General Packet Thread Pool:\r\n");
			tb.append("Tasks in the queue: "
					+ _generalPacketsThreadPool.getQueue().size() + "\r\n");
			tb.append("Showing threads stack trace:\r\n");
			PriorityThreadFactory ptf = (PriorityThreadFactory) tf;
			int count = ptf.getGroup().activeCount();
			Thread[] threads = new Thread[count + 2];
			ptf.getGroup().enumerate(threads);
			tb.append("There should be " + count + " Threads\r\n");
			for (Thread t : threads) {
				if (t == null)
					continue;
				tb.append(t.getName() + "\r\n");
				for (StackTraceElement ste : t.getStackTrace()) {
					tb.append(ste.toString());
					tb.append("\r\n");
				}
			}
		}
		tb.append("Packet Tp stack traces printed.\r\n");
		return tb.toString();
	}

	public String getIOPacketStats() {
		TextBuilder tb = new TextBuilder();
		ThreadFactory tf = _ioPacketsThreadPool.getThreadFactory();
		if (tf instanceof PriorityThreadFactory) {
			tb.append("I/O Packet Thread Pool:\r\n");
			tb.append("Tasks in the queue: "
					+ _ioPacketsThreadPool.getQueue().size() + "\r\n");
			tb.append("Showing threads stack trace:\r\n");
			PriorityThreadFactory ptf = (PriorityThreadFactory) tf;
			int count = ptf.getGroup().activeCount();
			Thread[] threads = new Thread[count + 2];
			ptf.getGroup().enumerate(threads);
			tb.append("There should be " + count + " Threads\r\n");
			for (Thread t : threads) {
				if (t == null)
					continue;
				tb.append(t.getName() + "\r\n");
				for (StackTraceElement ste : t.getStackTrace()) {
					tb.append(ste.toString());
					tb.append("\r\n");
				}
			}
		}
		tb.append("Packet Tp stack traces printed.\r\n");
		return tb.toString();
	}

	public String getGeneralStats() {
		TextBuilder tb = new TextBuilder();
		ThreadFactory tf = _generalThreadPool.getThreadFactory();
		if (tf instanceof PriorityThreadFactory) {
			tb.append("General Thread Pool:\r\n");
			tb.append("Tasks in the queue: "
					+ _generalThreadPool.getQueue().size() + "\r\n");
			tb.append("Showing threads stack trace:\r\n");
			PriorityThreadFactory ptf = (PriorityThreadFactory) tf;
			int count = ptf.getGroup().activeCount();
			Thread[] threads = new Thread[count + 2];
			ptf.getGroup().enumerate(threads);
			tb.append("There should be " + count + " Threads\r\n");
			for (Thread t : threads) {
				if (t == null)
					continue;
				tb.append(t.getName() + "\r\n");
				for (StackTraceElement ste : t.getStackTrace()) {
					tb.append(ste.toString());
					tb.append("\r\n");
				}
			}
		}
		tb.append("Packet Tp stack traces printed.\r\n");
		return tb.toString();
	}
}